E-commerce has seen enormous growth in the past few decades. The prospect of buying a product online and having it shipped to one's address makes the process of buying and selling quick and easy. However, the process of buying and selling a product online often involves navigation through multiple web pages. In the process of selling, a user must often input data about his product on a third-party website such as ebay.com or craigslist.com. Posting a product to sell often involves navigation through many pages. The other option often involves building an entire online store. And once a product is added to a site, marketing usually involves organic searches for the product or expensive advertising of the product. Purchasing a product can be equally frustrating for customers on these online marketplaces. In the process of buying, users are often prompted to select a product on one page, add it to their shopping carts that are displayed on other pages, and then check out by providing their billing and delivery data on yet another series of pages. The time involved in this process can be especially costly and cumbersome when a user attempts to perform the buying transaction on a mobile device. Furthermore, when encountering a product on a social network or blog, purchasing the item often disrupts the user from their current activity on the social network or blog. For example, if a user posts a link to a product website in a content stream of a social network, a user is directed to that link outside of the social network after clicking the link. Thus, there is a need in the e-commerce field to create a new and useful system and method for selling a product through an adaptable purchase interface. This invention provides such a new and useful system and method.